Rejected queries for mx???.emailfiltering.com

[Chris Adams]

Once upon a time, Phil Mayers  <p.mayers at imperial.ac.uk> said:
>On the subject of rejected queries - although this isn't a bind question 
>per-se, I'm curious if anyone else here sees a lot of these:
>
>client 178.123.92.141#23861: view main: query (cache) 
>'mx242.emailfiltering.com/A/IN' denied
>
>We get *loads* of them to our authoritative resolvers. I am assuming 
>they are attempts at cache poisoning given the (ahem) dubious 
>geographical origin of the queries (no offense intended to anyone living 
>in those parts of the world) but I can't see any corresponding inbound 
>forged DNS packets in our netflow.

Do you have domains listing mx242.emailfiltering.com as an MX?  I have
seen some broken resolvers that will do an MX lookup and then turn
around and do A lookups for the MX hosts at the same DNS server.

-- 
Chris Adams <cmadams at hiwaay.net>
Systems and Network Administrator - HiWAAY Internet Services
I don't speak for anybody but myself - that's enough trouble.